Extruded ceiling fan blade and method of making blade

ABSTRACT

Novel extruded ceiling fan blades, compositions and methods of making the blades from plastic material such as polystyrene are disclosed. The blades can be formed from two extruders so that different colors and/or finishes, such as wood grain looks can be formed on the upper and lower surfaces of the blades.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Divisional of U.S. patent application Ser. No.13/923,927 filed Jun. 21, 2013, now U.S. Pat. No. 9,605,546, whichclaims the benefit of priority to U.S. Provisional Application Ser. No.61/662,445 filed Jun. 21, 2012. The entire disclosure of each of theapplications listed in this paragraph are incorporated herein byspecific reference thereto.

FIELD OF INVENTION

This invention relates to ceiling fans, and in particular to extrudedceiling fan blades, compositions and methods of making solid ceiling fanblades formed from polystyrene.

BACKGROUND AND PRIOR ART

Traditional types of ceiling fan blades have been formed from solid woodand molded plastic core type materials, such as ABS(AcrylonitrileButadiene Styrene) or PVC (poly vinyl chloride). See for example, U.S.Pat. No. 5,669,760 to Chen. However, there are increasing numbers ofproblems with using these types of materials.

For example, wood and ABS and PVC blades can warp over time when exposedto different heat temperatures, and can become both unsightly,unbalanced and must be replaced.

Additionally, the solid core wood and ABS and PVC blades require morepower and electrical costs to rotate their masses over lighter weightmaterials, which further increases the costs of operation whenever theceiling fans use three or more blades or the fans have larger diameterwingspans.

Using light weight versions of these materials such as balsa wood andthin plastic is not practical since the blades can wobble and easilychip, crack and break during use.

Still furthermore, traditional wood and ABS and PVC blades can becomeunstable due to continuous UV (ultra violet) exposure, and wood surfacescan also fade over time.

Additionally, the cost of wood or wood substitute products such as MDF(medium density fibreboard) has become increasingly expensive over timeand untreated wood is not resistant to mold and mildew which furthereffects the cost since the lifespan of the blades may be reduced overtime. Wood type materials can be prone to absorbing moisture which canadd to the weight as well as the mold and mildew effects. MDF is proneto drooping over time.

The cost of ABS type plastics have also become increasingly expensiveovertime since plastic is petroleum based which has become substantiallymore and more expensive over time. There are other disadvantages tousing ABS plastic that include limited weather resistance and moderateheat, moisture and chemical resistance which would limit the use of thismaterial to outdoor fans. Additionally, ABS is highly flammable withhigh smoke generation which would make its' use further undesirable inresidential or commercial locations as being a fire hazard. PVC hassimilar problems. Modifying ceiling fans to add colors, such as woodgrain surfaces, and different color tints has not been an inexpensiveprocess. Currently wood blades would need to be stained and coated withadditional water proof coatings. Similarly ABS and PVC type plastic fanblades need separate colored coatings. Molded plastic blades may be ableto be formed having single color. However, changing the color on sidegenerally requires painting on a different surface coating. Thus, tochange the outer colors of traditional wood and molded ABS or plastic orPVC blades adds additional labor and material costs which are thenpassed onto the consumer.

Thus, the need exists for solutions to the problems with the prior art.

SUMMARY OF THE INVENTION

A primary objective of the present invention is to provide polystyreneextruded ceiling fan blades, compositions and methods of making theblades.

A secondary objective of the present invention is to provide polystyreneplastic extruded ceiling fan blades that are lighter in weight than woodblades.

A third objective of the present invention is to provide thermoplasticextruded ceiling fan blades that are approximately 15-20% lighter inweight than molded ABS plastic blades.

A fourth objective of the present invention is to provide thermoplasticextruded ceiling fan blades that is up to some 50% or more, lessexpensive than ABS plastic injection molded blades.

A fifth objective of the present invention is to provide thermoplasticextruded ceiling fan blades using material that is resistant to warpingfrom heat.

A sixth objective of the present invention is to provide extrudedceiling fan blades using material that is water resistant, moldresistant and mildew resistant.

A seventh objective of the present invention is to provide extrudedceiling fan blades using material that does not absorb moisture ascompared to MDF, plywood and existing hybrid ceiling fan bladematerials, and is more resistant to not drooping overtime.

An eighth objective of the present invention is to provide extrudedceiling fan blades using material that remains stable under continuousUV (ultra violet) exposure.

A ninth objective of the present invention is to provide extrudedceiling fan blades using material that is resistant to fading whencontinuously exposed to light and UV wavelengths.

A tenth objective of the present invention is to provide extrudedceiling fan blades, compositions and methods of making the blades, thatform 100% waterproof blades

An eleventh objective of the present invention is to provide extrudedceiling fan blades, that can use smaller motors than traditional bladeswhich improves the efficiency of the ceiling fan.

A twelfth objective of the present invention is to provide extrudedceiling fan blades, that require less power (in watts) than traditionalblades which improves the efficiency of the ceiling fan.

A thirteenth objective of the invention is to provide extruded ceilingfan blades, compositions and methods of making the blades, where colorsdo not have to be separately painted and/or stained on the surface.

A fourteenth objective of the invention is to provide extruded ceilingfan blades, compositions and methods of making the blades, that allowsfor having different colors on each side of the blades without stainsand paints.

A method of making a ceiling fan blade having different colored surfacescan include the steps of providing a first extruder and a secondextruder, supplying polystyrene plastic having a first color in thefirst extruder, supplying polystyrene plastic having a second color intothe second extruder, the second color being a different color from thefirst color, combining a first part feeding out of the first extruderwith a second part feeding out of the second extruder into a dye, andextruding a single ceiling fan blade from the combined first part andsecond part, the blade having an upper surface with the first color andthe blade having a lower surface with the second color.

The method can include the step of post processing the single ceilingfan blade.

The post processing step can include the step of cutting off an endportion to shorten the ceiling fan blade.

The post processing step can include the step of drilling holes in oneend of the blade for attaching to a blade arm.

The post processing step can include the step of sanding or routing theceiling fan blade.

The providing step can include the step of providing a first feed screwas the first extruder and a second feed screw as the second feed screw.

The method can include extruding at least one surface with a wood grainsurface effect.

The supplying step can include the step of providing a first hopper forholding first polystyrene pellets of the first color to supply the firstextruder, and providing a second hopper for holding second polystyrenepellets of the second color to supply the second extruder.

The method can include an outlet for extruding a concave curved ceilingfan blade.

The extruding step can include an outlet for extruding a substantiallyflat surfaced ceiling fan blade.

The extruding step can include an outlet for forming a leading edge anda trailing edge on the blade, the leading edge being narrower than thetrailing edge.

A composition can include different colors of polystyrene extruded intoa single ceiling fan blade.

A ceiling fan blade can include a first layer formed from extrudedpolystyrene of a first color, the first layer having an upper surfaceand a lower surface, and a second layer formed from extruded polystyreneof a second color, the first color being different from the secondcolor, the second layer having an upper surface and a lower surface, thelower surface of the first layer adhering to the upper surface of thesecond layer, so that the first color of the upper surface of the firstlayer and the second color of the lower surface are visibly exposed.

The blade can include holes in one end of the first layer and the secondlayer adapted for attaching the ceiling fan blade to a blade arm.

The blade can include sanded or routed edges on the ceiling fan blade.

The blade can include an outer edge cut off to shorten the length of theceiling fan blade.

Further objects and advantages of this invention will be apparent fromthe following detailed description of the presently preferredembodiments which are illustrated schematically in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a flow chart of the basic method steps to form an extrudedceiling fan blade.

FIG. 2 shows a top view of an extruder machine for forming the extrudedceiling fan blades of the invention with different colored sides.

FIG. 3 is a side view of the extruder machine of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before explaining the disclosed embodiments of the present invention indetail it is to be understood that the invention is not limited in itsapplications to the details of the particular arrangements shown sincethe invention is capable of other embodiments. Also, the terminologyused herein is for the purpose of description and not of limitation.

FIG. 1 is a flow chart of the basic method steps to form an extrudedceiling fan blade. The first step 100 includes supplying polystyrenehaving a first color into a first extruder and supplying polystyrenehaving a second color into a second extruder, where the first color andthe second color are different. The second step 200 includes extrudingout a first part and a second part from the first extruder and thesecond extruder. The third step 300 combining the first part and thesecond part into a dye to shape a single ceiling fan blade therefrom.The next steps are post-processing the fan blade as needed. For example,the fourth step 400 can include cutting blade part into a ceiling fanblade shape. The fifth step 500 can include drilling holes in the fanblade for attachment to blade arms. The sixth step 600 can includesanding leading and trailing edges of the blade to a desired andselected shape. Alternatively, the dye can shape the blade to havingflat surfaces, or concave/convex surfaces. Additionally, the dye canalso form narrower leading edges and wider trailing edges as needed.

Additionally, the fourth, fifth and sixth steps can include additionalpost-processing to finish the blade such as a router to further shapethe blade and holes drilled for attaching the blade to blade arms.

FIG. 2 shows a top view of an extruder machine 1 for forming theextruded ceiling fan blades of the invention with different coloredsides. FIG. 3 is a side view of the extruder machine 1 of FIG. 2.

Polystyrene pellets are the preferred source of material since otherplastics, such as but not limited to PVC do not work under fieldconditions such as UV light conditions, and the like. ABS plastic hasother problems making it undesirable as referenced in the backgroundsection of this application.

Referring to FIGS. 1-2, a pair of extruders, can each include a hopper10, 20 that feed a plurality of polystyrene pellets into one end ofbarrels 14, 24. Screw conveyors 14, 24 in the barrels are rotated byelectric motors 12, 22. Such screw type extruders can be such as thosein U.S. Pat. No. 2,174,779, which is incorporated by reference.

Here the screws are used to push the pellets through the barrels 14, 24.Heat is applied in the barrels to melt the pellets to the breaker plates16, 26. The breaker plates 16, 26 can be a thick metal puck with manyholes drilled through it) since the pressure at this point can exceedapproximately 5000 psi (approximately 34 MPa). The breaker plateassembly also serves to create back pressure in the barrels. Backpressure can be required for uniform melting and proper mixing of thepolymer, and how much pressure is generated can be ‘tweaked’ by varyingscreen pack composition (the number of screens, their wire weave size,and other parameters). This breaker plate and screen pack combinationalso does the function of converting “rotational memory” of the moltenplastic into “longitudinal memory”. Approximately would be +/−10%.

The breaker plates 16, 26 directs respective extruded parts intorespective feed pipes 18, 28 and into ends 32, 34 of a dye 30.

The die 30 is what gives the final product its profile and must bedesigned so that the molten plastic evenly flows from a cylindricalprofile, to the product's profile shape.

The profile shape can be a rectangular slit to form a substantially flatblade, a frown shaped slit to form a concave/convex shaped blade, andthe like. Conventional heat can be used to melt the pellets (eat withCompression used to form and customize the blade shapes. Narrow leadingedges and wider trailing edges can be formed as selected.

As described above dye 30 can be formed with an outlet that can shapethe extruded finished ceiling fan blade to have substantially flatsurfaces. Alternatively, the blade can be shaped by an outlet to formceiling fan blades with concave curved one side and convex curved on oneside.

The pellets in the hoppers 10, 20 can be selected so that the finishedblade has a different color on an upper surface than the lower surface.Additionally, the pellets can allow for one or both outer surfaces ofthe blade to have a wood grained effect surface. As such, the finishedceiling fan blades do not have be separately stained and/or painted asthose blades in the prior art.

A completed ceiling fan blade is extruded from the outlet 36 of the dye.As referenced above, various types of post processing steps can occur,such as but not limited to cutting off the end of the blade to shortenit, sanding and/or grouting edges, and the like, and drilling holes inone of the blade in order to attach the blades to ceiling fan arms ordirectly to rotors on ceiling fan motors.

Density of the material when extruded can be adjusted by the pressure.The more dense the material the harder the resulting product and theless the amount of closed pores in the product. The invention does notneed or require having to separately stain or paint the exterior of theblades.

The novel polystyrene extruded blades are less expensive than the priorart ABS plastic blades. The polystyrene extruded blades are lighter thanABS and are able to use smaller, cheaper motors to achieve the same airmovement.

Alternatively, using the polystyrene blades with standard size motorscan achieve increased air movement (more CFM (cubic feet per minute ofairflow)) at less cost than using ABS plastic blades with standardmotors.

The novel polystyrene extruded blades are stronger than MDF blades andare more resistant to drooping over time, which occurs with wood and MDFblades. The polystyrene extruded blades are more resistant to UV thanPVC (polyvinyl chloride) material.

Unlike the prior art methods of making blades, polystyrene extrudedblades can be extruded with two different colors on each side of blade.This eliminates the labor and material costs from having to paint thefinished ABS or PVC blades. The novel extrusion techniques usingpolystyrene is able to be extruded with a wood grain pattern that ispopular for ceiling fans blades.

While the invention has been described, disclosed, illustrated and shownin various terms of certain embodiments or modifications which it haspresumed in practice, the scope of the invention is not intended to be,nor should it be deemed to be, limited thereby and such othermodifications or embodiments as may be suggested by the teachings hereinare particularly reserved especially as they fall within the breadth andscope of the claims here appended.

We claim:
 1. A method of making a ceiling fan blade having differentcolored surfaces consisting of the steps of: providing a first extruderand a second extruder; supplying a first color in the first extruder;supplying a second color into the second extruder, the second colorbeing a different color from the first color; uniformly heating each ofthe first color and the second color, to form uniform melting and mixingof the first color and to form uniform melting and mixing of the secondcolor, wherein the step of uniformly heating includes forming a backpressure that exceeds approximately 5000 psi; combining a first partfeeding out of the first extruder with a second part feeding out of thesecond extruder to evenly flow into a die; and extruding a singleceiling fan blade from the combined first part and second part, theblade having an upper surface with the first color and the blade havinga lower surface with the second color; and post processing the singleceiling fan blade, wherein at least one of the upper surface and thelower surface of the blade has a wood grain finish formed from at leastone of the first color and the second color, and not by post processing.2. The method of claim 1, wherein the step of providing a first extruderand a second extruder includes the steps of: providing a first feedscrew in a first barrel as the first extruder and a second feed screw ina second barrel as the second extruder.
 3. The method of claim 1,wherein the supplying steps includes the steps of: supplying polystyrenepellets having the first color in the first extruder; supplyingpolystyrene pellets having the second color in the second extruder. 4.The method of claim 1, wherein the forming step includes the step of:forming the back pressure that exceeds the approximately 5000 psi with afirst breaker plate having a plurality of holes and forming a backpressure with a second breaker plate having a plurality of holes andadjusting the back pressure in the first breaker plate and the backpressure in the second breaker plate with wire screens.
 5. The method ofclaim 1, wherein the post processing step includes the step of: cuttingoff an end portion to shorten the ceiling fan blade.
 6. The method ofclaim 1, wherein the post processing step includes the step of: drillingholes in one end of the blade for attaching to a blade arm.
 7. Themethod of claim 1, wherein the post processing step includes the stepof: sanding or routing the ceiling fan blade.
 8. The method of claim 1,wherein the extruding step includes: an outlet for extruding a concavecurved ceiling fan blade.
 9. The method of claim 1, wherein theextruding step includes: an outlet for extruding a substantially flatsurfaced ceiling fan blade.
 10. The method of claim 1, wherein theextruding step includes: an outlet for forming a leading edge and atrailing edge on the blade, the leading edge being narrower than thetrailing edge.